Re: reload question

[Miles Bader <miles at lsi dot nec dot co dot jp>]

Ian Lance Taylor <ian@airs.com> writes:
> I agree that gcc is not well designed to cope with an accumulator
> architecture.  Reload can't cope.

I've had a fair amount of success with the approach I initially posted
(perturbing the emission order of reloads based on dependencies between
the operand they are associated with).  It's still pretty fragile in the
sense that even a tiny mistake in something like the constraints will
cause reload to barf, but I guess that's to be expected.  The code
produced seems pretty reasonable too (with almost no peepholes at all);
for instance it will allocate a variable to the accumulator in the odd
case where that's possible.

[I don't know if this is the sort of thing that's viable for merging
into standard gcc, but maybe a simpler approach based on a backend hook
or something would be.]

I gotta admit though, by now I thoroughly hate the gcc reload code...

-Miles
-- 
((lambda (x) (list x x)) (lambda (x) (list x x)))